How do I set up an iphone and keep the same number?

Depending on the size of your current SIM and as long as your last phone wasn't an older blackberry , it may be just as simple as moving your sim from one device to the other.

If the Sims are a different size you'll need to get the right size and you can transfer your service to it yourself via self serve... Phone services.

If you're comming from a carrier other than Koodo you'll need to get a koodo sim and then during Activation you'll be asked to provide details about your account at the other carrier. Make sure to keep your old number active with your old carrier. Koodo will handle cancelling your service with them and grabbing the number. Your iPhone will either need to be a koodo/Telus iPhone or be unlocked. Koodo cannot unlock iPhone from other carriers so best to ask your carrier to unlock before you port out.